This invention is related to copending application Ser. No. 81188 concurrently filed herewith and which is assigned in common with the present application.
This invention relates generally to photographic apparatus and, more particularly, to an improved snap-together tamper resistant stroke housing.
In the photographic field, electrically fired strobe units for transient illumination of scenes to be photographed have gained wide acceptance. In use of such strobes, it is necessary to use relatively high amounts of electrical power for achieving the desired illumination intensities required for proper scene lighting. Accordingly, it becomes imperative for safety reasons to provide a housing which suitably electrically insulates the user. Contemporaneous with this requirement are the requirements that the strobe unit be susceptible of convenient manufacture and assembly so as to enable production in a commercially competitive manner.
In regard to the latter requirements, it is known to provide housing components which can be easily assembled together in a snap-fit manner. Exemplary types of snap-fit housings are described in the following U.S. Pat. Nos. 3,346,210; 3,415,599; 3,617,013; 3,620,475; 3,712,557; 3,923,387; 4,015,790; 4,076,186; and 4,079,499. Generally, these housings are comprised of two plastic members having components which are flexible, yet stiff enough to enable a secure snap-fit interengagement. While such housings serve reliably, there is a potential for a user effecting snap-fit disengagement by merely laterally spreading or flexing the housing walls which carry the snap-fit components. Thus, although these housings facilitate easy assembly and can provide the necessary electrical insulation, there remains the possibility of a user relatively easily opening the housing. If used for strobes, there is possibility of the user exposing himself to the danger of electrical shock.
Attempts have been made to restrict or minimize disengagement of snap-fit members. One known approach is used in a snap together camera housing utilizing stop members on a first member cooperating with a flexible finger on a second member for restricting longitudinal reciprocation of the latching finger. While the foregoing approach is useful, it still suffers from the drawback that disengagement can be effected if the finger is moved laterally with respect to such longitudinal direction, as by a prying or flexing apart of the first and second members.
A successful approach for overcoming the foregoing problems is embodied in the aforenoted related copending application. As described therein, a snap-fit strobe housing is provided with mating first and second housing sections. Carried by and projecting from the first housing section is a flexible latching finger. A latching arrangement is provided on the interior of an exterior wall of the second housing section for flexing the finger into engagement therewith so as to prevent the housing sections being pulled apart in a given plane generally parallel to the plane of the exterior wall. Also included is retaining structure extending interiorly of the exterior wall in overlapping relationship to a surface of the finger facing away from the interior of the exterior wall so as to engage and retain the latching finger in continuous engagement with the latching arrangement and thereby prevent disengagement of the latching finger from the wall when pulled at an angle to the given plane. The foregoing arrangement serves very satisfactorily. For reasons of economics, less expensive plastics are desirable for strobe housing structure. However, some of the less expensive plastics are more easily flexed and use thereof in the foregoing described strobe housing lead to the potential problem of latching finger disengagement. Such disengagement could occur when the strobe housing end walls are manually gripped and flexed inwardly and then lifted. Consequently, the desired latching action would not be attained.